Reflective Half-wave Retardation Film Compensated Non-twisted Nematic Lcd Mode

in this paper, reflective uniaxial retardation film compensated non-twisted nematic liquid crystal display with single polarizer was studied to solve the problem of large color dispersion existing in reflective non-twisted nematic liquid crystal display. This research result would help to realize direct-view type reflective full color liquid crystal display. Based on Jones matrix method, a novel reflective LCD mode named Reflective Half-wave retardation film compensated Non-Twisted Nematic LCD mode (RH-NTN mode) was proposed after rigorous analytical deduction. The effect of the position of both half-wave retardation film and direction of liquid crystal director on LCD抯 color dispersion was discussed. An optimized configuration was achieved which not only decreases the color dispersion at dark state to the lowest extent but also makes the color dispersion at bright 4 state be comparable with that of optimized MTN mode. These outstanding characteristics make RH-NTN mode to be promising for direct-view type reflective full color LCD. The optical performance of both Reflective Half-wave retardation film compensated Parallel Aligned Nematic LCD (RH-PAN LCD) and Reflective Half-wave retardation film compensated Hybrid Aligned Nematic LCD (RH- HAN LCD), which are both from RH-NTN mode, was analyzed with 4x4 matrix method. The simulation results showed that both of these two types of LCD work on normal black mode and have the problems of serious blue color shift at dark state and over-high driving voltage. In order to solve these problems, the central wavelength was reduced to 520nm and an extra uniaxial 2 Abstract retardation film was added. As a result, a normal white mode was achieved and both the driving voltage and blue color shift were effectively decreased. Numerical simulation results also showed that the characteristics of both uniaxial film compensated RH-PAN LCD and uniaxial film compensated RH-. HAN LCD are attractive. The reflectance is 35.1% and 34.9%, respectively, and contrast ratio reaches 40:1 and 47:1, respectively. At the same time, the chromatic performance is comparable to that of optimized MTN mode. Therefore, both uniaxial film compensated RH-PAN LCD and uniaxial film compensated RH-HAN LCD can realize direct-view type reflective fulliolor LCD with high reflectance and high contrast ratio. In order to verify the novel RH-NTN mode presented here, some experiments were carried out for both RH-HAN LCD and uniaxial retardation film compensated RH-HAN LCD. Good agreement was achieved between experimental results and simulation results. Since both of these two types of LCD are based on RH-NTN mode, the experiments verified the correctness of RH-NTN mode.